Narrative:

Near midair #1; on approach to runway 1 at gua. IFR flight plan; altimeter setting 30.32 WX VFR. At 6000 ft MSL cleared to land from tower. 'Traffic alert' on TCAS and had visual on aircraft on a left downwind to runway 1 and on a heading parallel to me and then he started to turn in behind me and got an RA to climb. Did go around with traffic in sight as he turned in behind me. First officer informed tower of the GA. Leveled off at 7000 ft MSL after RA stopped. No hard evasive action and no injuries. Lots of chatter on the frequency; all in spanish. Tower acknowledged our go around and we tried to query about what the tower wanted us to do; no answer. Switched to approach and informed them about GA and requested to enter left downwind to runway 1. Approach approved the request and started left turn while clearing the turn and contacted the tower. He acknowledged and cleared us to land and no traffic warnings. Entered downwind at 7000 ft MSL; still dirty at flaps 5 plus 10. Still clearing for traffic. Informed passenger and flight attendant; over PA about the GA for traffic and would be landing in a few mins. Near midair #2. First officer backed up the landing checklist on the downwind and I was getting my spacing abeam the runway and saw an aircraft to my left at my altitude on a vector into me. He turned hard right to pass behind me. He passed within 500 ft or less. I did not have time to respond. It all happened too fast. There was no TCAS warning. The other aircraft did not show on my TCAS display. I would have to assume that his transponder was off. There was no traffic warning from the tower. Continued the visual approach to runway 1 that was uneventful. Still lots of chatter on tower frequency. After landing on ground frequency we informed ATC of the near midair and they said 'sorry.' just another day at the office.

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Original NASA ASRS Text

Title: AN ACR ARRIVING MGGT EXPERIENCED NMACS ON TWO APCHS. ONE WITH AN EVASIVE TCAS GAR AND A SECOND WITH NO TCAS; BUT THE CONFLICTING ACFT AT 500' OR LESS.

Narrative: NEAR MIDAIR #1; ON APCH TO RWY 1 AT GUA. IFR FLT PLAN; ALTIMETER SETTING 30.32 WX VFR. AT 6000 FT MSL CLRED TO LAND FROM TWR. 'TFC ALERT' ON TCAS AND HAD VISUAL ON ACFT ON A L DOWNWIND TO RWY 1 AND ON A HDG PARALLEL TO ME AND THEN HE STARTED TO TURN IN BEHIND ME AND GOT AN RA TO CLB. DID GAR WITH TFC IN SIGHT AS HE TURNED IN BEHIND ME. FO INFORMED TWR OF THE GA. LEVELED OFF AT 7000 FT MSL AFTER RA STOPPED. NO HARD EVASIVE ACTION AND NO INJURIES. LOTS OF CHATTER ON THE FREQ; ALL IN SPANISH. TWR ACKNOWLEDGED OUR GAR AND WE TRIED TO QUERY ABOUT WHAT THE TWR WANTED US TO DO; NO ANSWER. SWITCHED TO APCH AND INFORMED THEM ABOUT GA AND REQUESTED TO ENTER L DOWNWIND TO RWY 1. APCH APPROVED THE REQUEST AND STARTED L TURN WHILE CLRING THE TURN AND CONTACTED THE TWR. HE ACKNOWLEDGED AND CLRED US TO LAND AND NO TFC WARNINGS. ENTERED DOWNWIND AT 7000 FT MSL; STILL DIRTY AT FLAPS 5 PLUS 10. STILL CLRING FOR TFC. INFORMED PAX AND FLT ATTENDANT; OVER PA ABOUT THE GA FOR TFC AND WOULD BE LNDG IN A FEW MINS. NEAR MIDAIR #2. FO BACKED UP THE LNDG CHKLIST ON THE DOWNWIND AND I WAS GETTING MY SPACING ABEAM THE RWY AND SAW AN ACFT TO MY L AT MY ALT ON A VECTOR INTO ME. HE TURNED HARD R TO PASS BEHIND ME. HE PASSED WITHIN 500 FT OR LESS. I DID NOT HAVE TIME TO RESPOND. IT ALL HAPPENED TOO FAST. THERE WAS NO TCAS WARNING. THE OTHER ACFT DID NOT SHOW ON MY TCAS DISPLAY. I WOULD HAVE TO ASSUME THAT HIS XPONDER WAS OFF. THERE WAS NO TFC WARNING FROM THE TWR. CONTINUED THE VISUAL APCH TO RWY 1 THAT WAS UNEVENTFUL. STILL LOTS OF CHATTER ON TWR FREQ. AFTER LNDG ON GND FREQ WE INFORMED ATC OF THE NEAR MIDAIR AND THEY SAID 'SORRY.' JUST ANOTHER DAY AT THE OFFICE.

Data retrieved from NASA's ASRS site as of May 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.